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Abstract

Purpose: To model and predict the dynamics of conductive nonmagnetic objects within the MRI room under the influence of Lenz effect. Methods: The dynamics are described by an ordinary differential equation and the Lenz effect approximated by recognizing that the skin effect is negligible. This separated Lenz effect dependency on the object position and velocity, leading to a simple numerical procedure for objects of any shape. Results: The model and numerical procedure were validated with experimental data recording the rotation of an aluminum plate falling inside a 1.5 T MRI scanner. The model was also applied for studying the translation of an aluminum plate pushed with constant force towards the MRI bore through the fringe field. Conclusion: The collected results showed that it is possible to obtain accurate predictions of motion in the presence of Lenz effect by neglecting the skin effect while determining the electric currents induced in the metallic object during each infinitesimal motion step.